The present invention is concerned with maintenance of lateral orientation of the elongated flap-folding and flap-anchoring elevating heads of automatic carton closing machines of the types shown in U.S. Pat. Nos. Re. 26,440 of Aug. 13, 1968 (and its parent 3,236,022) and 3,496,697 of Feb. 24, 1970, during the up and down elevating movement of these heads despite the weight distribution of equipment mounted on them. The base structure of such a machine supports in a revised manner, for the purpose of the present invention, an upstanding tower structure or equivalent which, in turn, is provided for support and lifting and lowering thereon in a new manner such a head without hazarding longitudinal tipping resulting from unbalanced longitudinal distribution of forces. The disclosures of the above-identified U.S. Pat. Nos. Re. 26,440 and 3,496,697 are embodied herein by reference. The carton advancing path of the machine base structure and the tower structure are flanked on opposite sides by similar assemblies of guidance means and flexible tethers of relative allochiral arrangements, and these may be varied in the following manners while attaining the desired advantages and characteristic operations.
Most of such presently new arrangements of tower and tether supports of the flap-folding and flap-anchoring head, and lifting and lowering of the latter as may be required by the differing sizes of loaded cartons being processed therethrough, equip this elevating head on opposite sides with follower means or slides which are free to glide up and down in the opposed upright guide tracks provided by the opposite grooves of the upstanding channel members of the tower structure. In one such arrangement flexible tether means, e.g., a pair of lengths of cable or link chain, are allochirally provided on opposite sides of the elongated elevating head with one end of each anchored to a first portion of the elevator head and preferably by means of the slide mounted to the latter. Each such tether extends down below the elevating head to one of the first pair of guide means (which is on the same side of the lateral carton path of the frame base) and then laps up thereabout as an inverted loop. This flexible tether then extends up above the elevating head back over the one of a second pair of guide means which is also on the same side and finally down as a second loop on this same side to a second portion of the head which is appreciably spaced longitudinally from the first head portion. In this arrangement the first mentioned portion of the elongated elevating head is forward of the flap folding equipment carried thereby with this folding equipment being located in a second head portion that is in a trailing or rearward position. Also, it is preferred that the anchored end runs of the lower inverted and the upper tether loops extend substantially vertically with appreciable lateral distance therebetween, and thus for this purpose the upper loop laps simultaneously over an upper third guide means which is appreciably spaced to the rear of the second guide means.
The tower structure and/or the supporting base structure suitably support power driving means which is connected to the head for lifting and lowering the latter, and the lowering action may comprise chiefly free fall and checking thereof. For example, the top of the tower structure may carry a reversing motor as taught in U.S. Pat. No. 3,496,697 for lifting and lowering the elevating head by suitable driving means such as an endless chain and gearing including driven sprocket means. Also, for this purpose, such a driving motor may drive one or more sprockets meshed with the link chain tether on either or both sides of the machine. It may be preferred that such lifting and lowering of the elevating head be accomplished by operation of a double ended hydraulic motor, apart from such balancing tether suspensions immediately described, and which elevating mechanism is now well-known by virtue of the long use thereof in automatic carton closing machines taught in this U.S. Pat. No. 3,496,697.
It is to be understood that such balancing tether suspensions may be reversed in pattern by anchoring one end of the depending inverted loop at a rearward point on the second or trailing section of the flap-folding and carton-closing elevating head with the upwardly extending run of this loop lapping forwardly over the second and third top guide means finally to extend down to anchorage on the first forward section of the head. The follower means or slide on this same side of the head may be located at the rearward anchorage of the first-mentioned end of the tether, or any other convenient point along the head forward of such location.
Desirable characteristics and advantages of such balancing tether suspensions of the elevating flap-folding head may also be realized by training the flexible length of tether means from the forward point of anchorage directly or vertically down and rearwardly about the lower guide means below the head to extend then obliquely upward and rearwardly to above the head for lap rearward over the second guide means. The remaining end of the tether may then extend directly or vertically down from the rear side of this second uppermost guide means to anchorage on the head at the trailing or rearward point of fixation thereto. The follower means or slide may be mounted to the side of the head at any desired point along its length, e.g., at the forward point of tether anchorage, or the rearward point of such anchorage, or intermediate such points, etc. If desired, the guide means mounted upon the tower structure below and above the elevating head may be so located relative to the laterally spaced points of tether anchorage to the head that the runs thereof are arranged substantially at equal angles to vertical lines passing through the points of anchorage and the centers of the guide means with both of the latter located in the space between the spaced anchorage points. The latter arrangement may tend desirably to brace the lateral elongated head against tendency to rack or teeter, in supplement to the action of the follower means in the vertical tracks, in conditions of unbalancing operational forces.
It is an object of the invention to realize these and other related advantages in economical and reliable manners.
Another object of the invention is to provide such flexible tether guide means in the form of rotary disk means, such as free-running idler pulleys for cable tethers or free-running sprockets for link chain tethers.